My Dad has a 2000 Dutch Star with a cat diesel, the houselights won't come on, we put new house batteries in, I checked the owners's manual and it seems to lead back to MAYBE a GFCI switch, can anybody tell me where the switch might be located to reset it ? the owner's manual does NOT say where it's located just that it MIGHT be why the house batteries are not functioning. We also made up a set of new battery cables.